Point-in-time data replication method apparatus and system

Abstract

An apparatus, system, and method are disclosed for replicating point-in-time copies of local data to a remote site. The present invention mirrors point-in-time copy directives on the local data store to initiate a point-in-time copy operation on the remote copy of the local data, thereby efficiently providing remote access to a point-in-time copy of a dataset. Data integrity is ensured by committing local and remote point-in-time copy operations subsequent to successful initiation of both local and remote point-in-time copy operations. The present invention also, in one embodiment, rolls back a point-in-time copy operation in response to a failure to replicate the copy operation.

1 . An apparatus for local and remote replication of data, the apparatus: comprising: 
 a mirroring module configured to mirror local data to a remote data store in order to provide a remote copy of the local data;    a copy module configured to conduct a local point-in-time copy operation to provide a local point-in-time copy of the local data;    the copy module further configured to initiate a remote point-in-time copy operation on the remote data store [via a communication link in order to provide a remote point-in-time copy of the local data]; and    the copy module further configured to initiate reversion of the local point-in-time copy operation in response to failure of the remote point-in-time copy operation.    
   
   
       2 . The apparatus of  claim 1 , wherein the copy module is further configured to enter a commit state with regard to the local point-in-time copy operation in response to successful execution of the local and remote point-in-time copy operations.  
   
   
       3 . The apparatus of  claim 1 , wherein the copy module is further configured to initiate the remote point-in-time copy operation on the remote data store in response to receiving a point-in-time copy directive.  
   
   
       4 . The apparatus of  claim 1 , wherein the copy module is further configured to initiate the remote point-in-time copy operation on the remote data store by mirroring the point-in-time copy directive over a communication link.  
   
   
       5 . An apparatus for local and remote replication of data, the apparatus comprising: 
 a mirroring module configured to receive data from a remote data store in order to provide a local copy of remote data;    a copy module configured to receive a mirrored point-in-time copy directive from the remote data store and conduct a local point-in-time copy operation on the local copy of the remote data to provide a local point-in-time copy of the remote data; and    the copy module further configured to initiate reversion of the local point-in-time copy operation in response to failure of a remote point-in-time copy operation.    
   
   
       6 . The apparatus of  claim 5 , wherein the copy module is further configured to enter a commit state with regard to the local point-in-time copy operation in response to successful execution of the local and remote point-in-time copy operations.  
   
   
       7 . A system for local and remote replication of data, the system comprising: 
 a local data store configured to conduct a local point-in-time copy operation on local data;    the local data store further configured to mirror local data to a remote data store in order to provide a remote copy of the local data;    a remote data store configured to conduct a remote point-in-time copy operation on remote data;    the local data store further configured to mirror point-in-time copy directives on the local data store to the remote data store and thereby initiate a remote point-in-time copy operation on the remote copy of the local data; and    the local data store further configured to roll back the local point-in-time copy operation in response to a failure in the remote point-in-time copy operation.    
   
   
       8 . The system of  claim 7 , wherein the remote data store is further configured to revert the remote point-in-time copy operation in response to a failure in the local point-in-time copy operation.  
   
   
       9 . The system of  claim 7 , wherein the local and remote data stores are further configured to enter a commit state with regard to the local and remote point-in-time copy operations in response to successful execution of the local and remote point-in-time copy operations.  
   
   
       10 . A signal bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform an operation for local and remote replication of data, the operation comprising: 
 mirroring local data to a remote data store in order to provide a remote copy of the local data;    conducting a local point-in-time copy operation to provide a local point-in-time copy of the local data;    initiating a remote point-in-time copy operation on the remote data store to provide a remote point-in-time copy of the local data; and    initiating reversion of the local point-in-time copy operation in response to failure of the remote point-in-time copy operation.    
   
   
       11 . The signal bearing medium of  claim 10 , further comprising entering a state committing the local point-in-time copy operation in response to successful execution of the local and remote point-in-time copy operations.  
   
   
       12 . The signal bearing medium of  claim 10 , further comprising committing the remote point-in-time copy operation in response to successful execution of the local and remote point-in-time copy operations.  
   
   
       13 . The signal bearing medium of  claim 10 , wherein conducting the local point-in-time copy operation occurs in response to receiving a point-in-time copy directive.  
   
   
       14 . The signal bearing medium of  claim 10 , wherein initiating the remote point-in-time copy operation on the remote data store occurs in response to receiving a point-in-time copy directive.  
   
   
       15 . The signal bearing medium of  claim 10 , the operation further comprising committing the point-in-time copy directives in response to a determination of an absence of errors.  
   
   
       16 . The signal bearing medium of  claim 15 , further comprising responding to a point in time copy failure by: 
 rolling back any point-in-time data copy procedures successfully completed;    rolling back local and remote point-in-time data copy procedures upon failure of the local copy commit; and    performing a failure recovery procedure upon failure of the remote copy commit according to configurable parameters, the failure recovery procedure selected from returning a copy failure status to the calling procedure, and allowing data copying to be completed by a data mirroring system.    
   
   
       17 . A method for local and remote replication of data, the method comprising: 
 initiating local point-in-time data copy procedures;    mirroring local data to a remote data store in order to provide a remote copy of the local data; and    mirroring local point-in-time data copy directives to a remote data store.    
   
   
       18 . The method of  claim 17 , the method further comprising making a decision to commit or roll back point-in-time copy directives.  
   
   
       19 . The method of  claim 17 , further comprising responding to a point-in-time data copy failure.  
   
   
       20 . The method of  claim 17 , wherein responding to a point-in-time data copy failure comprises: 
 rolling back any point-in-time data copy procedures successfully completed;    rolling back local and remote point-in-time data copy procedures upon failure of the local copy commit; and    performing a failure recovery procedure upon failure of the remote copy commit according to configurable parameters, the failure recovery procedure selected from returning a copy failure status to the calling procedure, and allowing data copying to be completed by a data mirroring system.    
   
   
       21 . An apparatus for local and remote replication of data, the apparatus comprising: 
 means for initiating local point-in-time data copy procedures;    means for mirroring local data to a remote data store and thereby providing a remote copy of the local data; and    means for mirroring local point-in-time data copy directives to a remote data store.    
   
   
       22 . The apparatus of  claim 21 , the apparatus further comprising means for entering a state committing local and remote point-in-time data copies.  
   
   
       23 . The apparatus of  claim 21 , further comprising means for responding to point-in-time data copy failure.  
   
   
       24 . The apparatus of  claim 22 , wherein the means for responding to point-in-time data copy failure further comprises: 
 means for rolling back any point-in-time data copy procedures successfully completed;    means for rolling back local and remote point-in-time data copy procedures upon failure of the local copy commit; and    means for performing a failure recovery procedure upon failure of the remote copy commit according to configurable parameters, the failure recovery procedure selected from returning a copy failure status to the calling procedure, and allowing data copying to be completed by a data mirroring system.